Suppressor effect questions

[JAYgs8163]

I recently picked up my new Surefire SOCOM300 gen2 after a 9 month wait. Being a rookie to the suppressed rifle shooting I have some questions I was hoping I could get some help with here. My POI shift is about 2" low at 100 yards on the 2 different loads I shot out of 2 different rifles of 2 different calibers. I was curious if this is due to decreased MV or is it due to the added weight of the suppressor and the changing of barrel harmonics? I did not have my Magnettospeed with me to test MV but I will check MV this weekend. I'm hoping the shift is due to the increased weight and change to barrel harmonics.

Secondly, does a load need to be developed to be shot suppressed? For instance if shooting a load towards the "max load" does one need to be concerned about increased pressures? Does a suppressed rifle increase pressure in a bolt action rifle?

Any tips are appreciated and thanks in advance for the answers and help.

JGS

 

[cohunt]

suppressors usually dont affect MV too much, and if they do they often times will increase the MV not decrease it
POI shift is real when using suppressors--sometimes a rifle will be more accurate with the suppressor, sometimes less--you may need to rework your load if you are not happy with the accuracy

barrel harmonics are changed, but shooter response to the different recoil impulse can change the POI also

 

[JAYgs8163]

suppressors usually dont affect MV too much, and if they do they often times will increase the MV not decrease it
POI shift is real when using suppressors--sometimes a rifle will be more accurate with the suppressor, sometimes less--you may need to rework your load if you are not happy with the accuracy

barrel harmonics are changed, but shooter response to the different recoil impulse can change the POI also

Thanks, accuracy was increased on both rifles. The suppressor requires the use of a muzzle break QD type attachment. Another question.

So if I am happy with accuracy I should be able to re-zero at 100 yards, measure MV, update my profiles in my GeoBallistics app and be back in business? Of course I would test at long range distances but I'm just curious.

 

[Unoboats]

correct

 

[JAYgs8163]

correct

Is it safe to assume if shooting a load that is near or at MAX load unsuppressed with no pressure signs or safety concerns, it should be ok to shoot it suppressed? This may be a better question for SUREFIRE.

 

[cohunt]

Is it safe to assume if shooting a load that is near, or at MAX load unsuppressed with no pressure signs or safety concerns, it should be ok to shoot it suppressed? This may be a better question for SUREFIRE.

semi auto or bolt gun?

 

[JAYgs8163]

semi auto or bolt gun?

Bolt but I also will shoot on a AR eventually

 

[Unoboats]

try not to use same brass for ar as bolt gun unless you have a redding body die, and even then i would not exchange between the two

 

[86alaskan]

You'll find a slight POI shift with most cans. The QD attach can exaggerate it a bit, but most current QD setups are very very good. If you're going to be shooting suppressed, work up your loads with the can, then double check performance with the can off. I work all my loads to be suppressed, then document the shift and accuracy change with the can off.

Your shift is most likely due to harmonics, not speed. I find better speed and consistency with the can. I think it acts as a blast chamber and allows pressures to kind of equalize before the bullet comes free. The can will cause back pressure increase on a had gun, but you won't need to worry about a bolt gun.

 

[cohunt]

bolt gun should be fine as far as pressures go, AR's will increase pressure to the gas port considerably (its actually not necessarily the pressure, more than the gas pulse time) and most AR's may need an adjustable gas block to reduce gas back to the bcg--AR's will often require a more narrow selection of powders if you hand load to get the gun to cycle reliably.

on my 223's I need about 2-4 clicks closed on the gas block when suppressed, on my 6.8's I need about 4 clicks less, the 308 I needs 6-8 clicks less for proper gas pressure to the bcg-- on my bolt guns I have never had any pressure issues or signs, but I do have a few that arent quite as accurate with the can, but more where the accuracy stays the same or increases with the can-- but all will shift POI a little with the cans I have

 

[spinal tap]

What's your barrel profile? I've found that POI changes are more consistent with heavier barrels. You may find that POI wanders as heat builds in the barrel and rifle. I've found a MagnetoSpeed RifleKuhl fan to be a huge help for cooling the rifle between groups.

 

[JAYgs8163]

Both rifles that I've shot so far Carbon Fiber wrapped. One is a Christensen Ridgeline in 6.5 Creedmoor and the other is a Custom 300 PRC with a 26" Proof Research CF wrapped barrel in Heavy Sendero. I've shot it on a another rifle also and POI is about 2" low on all three. All bolt guns. I've looked at the riflekuhl and will probably spring for one.

 

[John Klingenberg]

Velocity will increase, usually i get better accuracy with a can on. If you're switching the can around you'll have problems with a dancing zero. If it doesnt go on in the exact same place every time things change. Heres where you get hooked. You'll want a can on every rifle you own. I dont get much poi shift on the smaller calibers up to say .308. You can run max loads with no issues.

 

[spinal tap]

Both rifles that I've shot so far Carbon Fiber wrapped. One is a Christensen Ridgeline in 6.5 Creedmoor and the other is a Custom 300 PRC with a 26" Proof Research CF wrapped barrel in Heavy Sendero. I've shot it on a another rifle also and POI is about 2" low on all three. All bolt guns. I've looked at the riflekuhl and will probably spring for one.

I've been working with a CA Ridgeline in 6.5 PRC this year. I did not find an increase in MV with a SilencerCo Harvester can. However, I have found that the Ridgeline heats up pretty fast and my POI appears to shift higher as a result, which is something I've not found in other rifles. The shift isn't huge, but it's noticeable. 1.5-2" at 300 yds and 2.5-3" at 500 is what I've observed thus far.